Lock nut



FIG. 1 is a front/top side perspective view of the lock nut 1 according to my design;

FIG. 2 is a front view with the top side oriented up thereof;

FIG. 3 is a back view with the top side oriented down thereof;

FIG. 4 is a right side view with the top side oriented to the right thereof;

FIG. 5 is a left side view with the top side oriented to the left thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines are included for the purpose of illustrating portions of the structure that form no part of the claimed design. 

The ornamental design for a lock nut, as shown and described. 